How to Measure Water in Plants

Plants need water to survive, but too much or too little can be detrimental to their health. Therefore, it is crucial to find a way to measure the water content in plants accurately. There are several methods to measure water in plants, including:

1. Gravimetric Method

The gravimetric method involves weighing the plant tissue before and after drying to determine the amount of water present. To perform this method, collect a plant sample and weigh it on a scale. Then, dry the sample in an oven at around 70℃ for a few hours until it reaches a constant weight. Finally, weigh the dried sample again and subtract the weight of the dry plant material from the original weight to get the amount of water in the plant.

2. Tensiometer Method

A tensiometer measures the soil moisture content that the plant roots are exposed to, which helps determine the plant's water needs. To use a tensiometer, insert the tube into the soil near the plant's root system. The device measures the soil's tension, or the force required to extract the moisture. If the tension is low, the soil is moist, meaning the plant does not require water. However, if the tension is high, the soil is dry, and the plant may require watering.

3. Electrical Conductivity Method

The electrical conductivity (EC) method measures the water content in plants indirectly by measuring the electrical conductivity of the plant tissue. The more water the plant contains, the higher its electrical conductivity. To measure the plant's electrical conductivity, a small sample of the plant's tissue is taken and placed in distilled water to create a solution. A conductivity meter or multimeter measures the solution's conductivity, which can then be used to estimate the plant's water content.

4. Pressure Bomb Method

The pressure bomb method measures the water potential of a plant. Water potential is a measure of the plant's urge to absorb water from the soil. To use the pressure bomb method, cut off a leaf or stem from the plant, and measure its length and width. The sample is then placed in the pressure chamber, and pressure is applied to force water out of the leaf or stem. The pressure required to eject water is the plant's water potential, which can be used to determine the plant's watering needs.

Conclusion

There are several methods available to measure water in plants, such as the gravimetric, tensiometer, electrical conductivity, and pressure bomb method. Accurately measuring the water content in plants is vital to their health and growth, and understanding the plant's water needs can help ensure they are not over or under-watered. Choose the method that works best for your needs and use it to care for your plants properly.